public class Solution {
public int uniquePaths(int m, int n) {
int[][] dp = new int[m][n];
Arrays.fill(dp[0], 1);
for (int i = 1; i < m; i++) {
dp[i][0] = 1;
}
for (int i = 1; i < m; i++) {
for(int j = 1; j < n; j++) {
dp[i][j] = dp[i - 1][j] + dp[i][j - 1];
}
}
return dp[m - 1][n - 1];
}
}